Memory system

ABSTRACT

A memory system includes a memory controller, a first memory module including first and second groups of first memory chips, a second memory module including first and second groups of second memory chips, and a channel including a first group of signal lines suitable for coupling the memory controller with the first memory module, and a second group of signal lines suitable for coupling the memory controller with the second memory module.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/423,012 filed on Feb. 2, 2017, which claims priority to U.S. PatentApplication No. 62/290,697, entitled “MEMORY SYSTEM” filed on Feb. 3,2016. The disclosure of each of the foregoing application isincorporated herein by reference in its entirety.

TECHNICAL FIELD

This patent document relates to a memory system.

DISCUSSION OF THE RELATED ART

FIG. 1 is a configuration diagram illustrating a memory system includinga memory controller 110 and two memory modules 120 and 130.

Referring to FIG. 1, the memory modules 120 and 130 may include aplurality of memory chips DRAM0 to DRAM15, registering clock drivers 121and 131 and a plurality of buffer chips DB0 to DB7, respectively.

The memory chips DRAM0 to DRAM15 may be controlled by command signals,address signals and a clock signal provided from the memory controller110. The memory chips DRAM0 to DRAM15 may store data provided from thememory controller 110 and may read out stored data to the memorycontroller 110.

The registering clock drivers 121 and 131 may transfer to the pluralityof respective memory chips DRAM0 to DRAM15 the command signals, theaddress signals and the clock signal provided from the memory controller110.

Each of the buffer chips DB0 to DB7 may buffer the data transferredbetween the memory controller 110 and one or more corresponding memorychips among the plurality of memory chips DRAM0 to DRAM15.

Signals are transferred between the memory controller 110 and the memorymodules 120 and 130 through a channel CHANNEL which couples the memorycontroller 110 and the memory modules 120 and 130. The channel CHANNELtypically includes a plurality of lines for transferring the varioussignals. All the lines included in the channel CHANNEL are shared by thememory modules 120 and 130. However, in the case where at least twomemory modules 120 and 130 share lines in this way, the quality of thesignals transferred through the lines may deteriorate. In FIG. 1,illustration of the plurality of the lines of the channel CHANNEL fortransferring the various signals between the registering clock drivers121 and 131 and the respective memory chips DRAM0 to DRAM15 is omitted.

SUMMARY

Various embodiments are directed to a memory system with reduced loadingof a channel transferring signals between a memory module and a memorycontroller.

In an embodiment, a memory system may include: a memory controller; afirst memory module including first and second groups of first memorychips; a second memory module including first and second groups ofsecond memory chips; and a channel including a first group of signallines suitable for coupling the memory controller with the first memorymodule, and a second group of signal lines suitable for coupling thememory controller with the second memory module.

The first memory module may further include first and second groups offirst buffer chips, and the second memory module may further includefirst and second groups of second buffer chips.

The first buffer chips of the first group may be coupled between thefirst memory chips of the first group and the signal lines of the firstgroup, and the second buffer chips of the second group may be coupledbetween the second memory chips of the second group and the signal linesof the second group.

The first memory chips of the first group may exchange data with thesignal lines of the first group through the first buffer chips of thefirst group, and the first memory chips of the second group may exchangedata with the signal lines of the first group through the first memorychips of the first group and the first buffer chips of the first group.

The second memory chips of the second group may exchange data with thesignal lines of the second group through the second buffer chips of thesecond group, and the second memory chips of the first group mayexchange data with the signal lines of the second group through thesecond memory chips of the second group and the second buffer chips ofthe second group.

The first memory module may further include first data buses suitablefor transferring data between the first memory chips of the first groupand the first memory chips of the second group, and the second memorymodule may further include second data buses suitable for transferringdata between the second memory chips of the first group and the secondmemory chips of the second group.

The first memory chips of the first group may exchange data with thefirst buffer chips of the first group in the case where a first path isselected, and the first memory chips of the first group may transferdata between the first memory chips of the second group coupled with thefirst data buses and the first buffer chips of the first group in thecase where a second path is selected.

The second memory chips of the second group may exchange data with thesecond buffer chips of the second group in the case where a third pathis selected, and the second memory chips of the second group maytransfer data between the second memory chips of the first group coupledwith the second data buses and the second buffer chips of the secondgroup in the case where a fourth path is selected.

The first memory module may further include a first registering clockdriver, and the second memory module may further include a secondregistering clock driver.

The first memory chips of the first group and the first buffer chips ofthe first group may be disposed on a first side of the first registeringclock driver, and the first memory chips of the second group and thefirst buffer chips of the second group may be disposed on a second sideof the first registering clock driver.

The second memory chips of the first group and the second buffer chipsof the first group may be disposed on the first side of the secondregistering clock driver, and the second memory chips of the secondgroup and the second buffer chips of the second group may be disposed onthe second side of the second registering clock driver.

The signal lines of the first group may be coupled with the first memorymodule on the first side of the first registering clock driver, and thesignal lines of the second group may be coupled with the second memorymodule on the second side of the second registering clock driver.

The first memory chips of the first group may exchange data directlywith the signal lines of the first group, and the first memory chips ofthe second group may exchange data with the signal lines of the firstgroup through the first memory chips of the first group.

The second memory chips of the first group may exchange data directlywith the signal lines of the second group, and the second memory chipsof the second group may exchange data with the signal lines of thesecond group through the second memory chips of the first group.

The first memory module may further include first data buses suitablefor transferring data between the first memory chips of the first groupand the first memory chips of the second group, and the second memorymodule may further include second data buses suitable for transferringdata between the second memory chips of the first group and the secondmemory chips of the second group.

The first memory chips of the first group may exchange data with thesignal lines of the first group in the case where a first path isselected, and the first memory chips of the first group may transferdata between the first data buses and the signal lines of the firstgroup in the case where a second path is selected.

The second memory chips of the first group may exchange data with thesignal lines of the second group in the case where a third path isselected, and the second memory chips of the first group may transferdata between the second data buses and the signal lines of the secondgroup in the case where a fourth path is selected.

The first memory chips of the first group may be disposed in a firstrow, and the first memory chips of the second group may be disposed in asecond row.

The second memory chips of the first group may be disposed in a firstrow, and the second memory chips of the second group may be disposed ina second row.

One or more of the signal lines of the first group and the second groupmay be disposed alternately with each other.

The first memory module may further include a plurality of first bufferchips each of which is coupled between one or more of the signal linesof the first group and one or more of the first memory chipscorresponding thereto.

The second memory module may further include a plurality of secondbuffer chips each of which is coupled between one or more of the signallines of the second group, and one or more of the second memory chipscorresponding thereto.

Each of the first buffer chips may transfer data between thecorresponding first memory chips and the signal lines of the first groupwhich are coupled thereto, and each of the second buffer chips maytransfer data between the corresponding second memory chips and thesignal lines of the second group which are coupled thereto.

The first memory chips of the first group may be disposed in a firstrow, and the first memory chips of the second group may be disposed in asecond row.

Each of the first buffer chips may correspond to one or more of thefirst memory chips of the first group and one or more of the firstmemory chip of the second group.

The second memory chips of the first group may be disposed in a firstrow, and the second memory chips of the second group may be disposed ina second row.

Each of the second buffer chips may correspond to one or more of thesecond memory chips of the first group and one or more of the secondmemory chips of the second group.

One or more of the signal lines of the first group and the second groupmay be disposed alternately with each other.

In an embodiment, a memory system may include: a memory controller; afirst memory module comprising first and second groups of a plurality offirst memory chips, a first registering clock driver and first andsecond groups of a plurality of first buffer chips; a second memorymodule comprising first and second groups of a plurality of secondmemory chips, a second registering clock driver and first and secondgroups of a plurality of second buffer chips; a channel comprising firstand second groups of signal lines; a plurality of first data busescoupling each memory chip of the first group of the first memory chipswith a corresponding memory chip of the second group of the first memorychips; a plurality of second data buses coupling each memory chip of thefirst group of the second memory chips with a corresponding memory chipof the second group of the second memory chips, and wherein all of thefirst memory chips of the first memory module are controlled by thememory controller by employing the first group of the signal lines, andall of the second memory chips of the second memory module arecontrolled by the memory controller by employing the second group of thesignal lines.

The first memory chips of the first group may exchange data with thesignal lines of the first group through the first buffer chips of thefirst group, and the first memory chips of the second group may exchangedata with the signal lines of the first group through the first databuses, the first memory chips of the first group, and the first bufferchips of the first group.

The second memory chips of the second group may exchange data with thesignal lines of the second group through the second buffer chips of thesecond group, and the second memory chips of the first group mayexchange data with the signal lines of the second group through thesecond data buses, the second memory chips of the second group and thesecond buffer chips of the second group.

The first and second memory modules may further comprise a first and asecond path selection units, respectively, for selecting a data path.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram illustrating a memory system includinga memory controller and two memory modules.

FIG. 2 is a configuration diagram illustrating a memory system accordingto an embodiment of the present invention.

FIG. 3 is a diagram illustrating path selection of one of a first groupof memory chips in a first memory module of FIG. 2.

FIG. 4 is a configuration diagram illustrating a memory system accordingto another embodiment of the present invention.

FIG. 5 is a diagram illustrating a communication path between eachmemory chip and a memory controller included in the memory system ofFIG. 4.

FIG. 6 is a configuration diagram illustrating a memory system accordingto yet another embodiment of the present invention.

FIG. 7 is a diagram illustrating a communication path between eachmemory chip and a memory controller included in the memory system ofFIG. 6.

FIG. 8 is a diagram illustrating path selection of one of a first groupof memory chips in a first memory module of FIG. 6.

DETAILED DESCRIPTION

Although, various embodiments are described below in more detail withreference to the accompanying drawings, we note that the presentinvention may, however, be embodied in different forms and should not beconstrued as being limited only to the embodiments set forth herein.Rather, the described embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the presentinvention to those skilled in the art to which this invention pertains.Throughout the disclosure, like reference numerals refer to like partsthroughout the various figures and embodiments of the present invention.

It will be understood that, although the terms “first”, “second”,“third”, and so on may be used herein to describe various elements,these elements are not limited by these terms. These terms are used todistinguish one element from another element. Thus, a first elementdescribed below could also be termed as a second or third elementwithout departing from the spirit and scope of the present invention.

The drawings are not necessarily to scale and, in some instances,proportions may have been exaggerated in order to clearly illustratefeatures of the embodiments.

It will be further understood that when an element is referred to asbeing “connected to”, or “coupled to” another element, it may bedirectly on, connected to, or coupled to the other element, or one ormore intervening elements may be present. In addition, it will also beunderstood that when an element is referred to as being “between” twoelements, it may be the only element between the two elements, or one ormore intervening elements may also be present.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentinvention.

As used herein, singular forms are intended to include the plural formsas well, unless the context clearly indicates otherwise.

It will be further understood that the terms “comprises,” “comprising,”“includes,” and “including” when used in this specification, specify thepresence of the stated elements and do not preclude the presence oraddition of one or more other elements. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Unless otherwise defined, all terms including technical and scientificterms used herein have the same meaning as commonly understood by one ofordinary skill in the art to which the present invention belongs in viewof the present disclosure. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the present disclosure and the relevant art and will notbe interpreted in an idealized or overly formal sense unless expresslyso defined herein.

We further note that in the following description, numerous specificdetails are set forth in for providing a thorough understanding of thepresent invention. However, as would be apparent to those skilled in therelevant art, the present invention may be practiced without some or allof these specific details. In other instances, well-known processstructures and/or processes have not been described in detail in ordernot to unnecessarily obscure the present invention.

It is also noted, that in some instances, as would be apparent to thoseskilled in the relevant art, a feature or element described inconnection with one embodiment may be used singly or in combination withother features or elements of another embodiment, unless otherwisespecifically indicated.

Hereinafter, the various embodiments of the present invention will bedescribed with reference to the attached drawings.

FIG. 2 is a configuration diagram illustrating a memory system accordingto an embodiment of the present invention.

Referring to FIG. 2, the memory system may include a memory controller210, a first memory module 220, and a second memory module 230.

The first and second memory modules 220 and 230 may include a pluralityof memory chips DRAM0 to DRAM15, respective registering clock drivers221 and 231, and a plurality of buffer chips DB0 to DB7.

Operation of the memory chips DRAM0 to DRAM15 may be controlled by thememory controller 210 via a command signal, an address signal and aclock signal provided from the memory controller 210. The memory chipsDRAM0 to DRAM15 may thus be controlled to store data provided from thememory controller 210 and/or may read out stored data to the memorycontroller 210.

The memory chips DRAM0 to DRAM15 in each of the first and second memorymodules 220 and 230 may be divided into first and second groups DRAM_G0and DRAM_G1. The first and second groups DRAM_G1 and DRAM_G2 in each ofthe memory modules 220 and 230 may be disposed in first and second sidesD1 and D2 of the registering clock drivers 221 and 231, respectively. Ineach of the memory modules 220 and 230, the memory chips DRAM0 to DRAM15may be arranged in 2 rows and 8 columns.

In operation, the registering clock drivers 221 and 231 may transfer tothe plurality of respective memory chips DRAM0 to DRAM15 the commandsignal, the address signal and the clock signal provided from the memorycontroller 210. It is noted that the number of memory chips in eachmodule and their arrangement in rows and columns may vary from theillustrated embodiment of FIG. 2 without departing from the scope of thepresent invention.

Each of the buffer chips DB0 to DB7 of each module 220 and 230 maybuffer the data transferred between the memory controller 210 and one ormore corresponding memory chips among the plurality of memory chipsDRAM0 to DRAM15.

The buffer chips DB0 to DB7 of the first and second memory modules 220and 230 may be divided into a first group DB_G0 disposed in the firstside D1 and a second group DB_G1 disposed in the second side D2.

Signals are transferred between the memory controller 210 and the memorymodules 220 and 230 through a channel CHANNEL. The channel CHANNEL mayinclude a plurality of signal lines divided into first and second groupsL_G0 and L_G1.

In the first memory module 220, the buffer chips DB0 to DB3 of the firstgroup DB_G0 may be coupled with the signal lines of the first groupL_G0, and in the second memory module 230, the buffer chips DB4 to DB7of the second group DB_G1 may be coupled with the signal lines of thesecond group L_G1. Each of the buffer chips DB0 to DB7 may be coupledwith two memory chips of the same column.

The memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11 of the first groupDRAM_G0 and the memory chips DRAM4 to DRAM7 and DRAM12 to DRAM15 of thesecond group DRAM_G1 of geometrically corresponding disposition mayrespectively correspond to each other. For example, referring to FIG. 2,the memory chip DRAM0 of the first group DRAM_G0 and the memory chipDRAM4 of the second group DRAM_G1 have geometrically correspondingdisposition (i.e., left-lower side of the first and second groupsDRAM_G0 and DRAM_G1).

In the memory modules 220 and 230, data buses may be coupled betweencorresponding memory chips among the memory chips DRAM0 to DRAM3 andDRAM8 to DRAM11 of the first group DRAM_G0 and the memory chips DRAM4 toDRAM7 and DRAM12 to DRAM15 of the second group DRAM_G1. For example,referring to FIG. 2, the memory chip DRAM0 of the first group DRAM_G0and the memory chip DRAM4 of the second group DRAM_G1 are coupled toeach other through data buses DATA_BUS1 and DATA_BUS2. While only thedata buses DATA_BUS1 and DATA_BUS2 coupled between the memory chip DRAM0of the first group DRAM_G0 and the memory chip DRAM4 of the second groupDRAM_G1 are illustrated in FIG. 2 for the sake of convenience inillustration, it is to be noted that the data buses may be coupledbetween each of all the memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11of the first group DRAM_G0 and each of all the memory chips DRAM4 toDRAM7 and DRAM12 to DRAM15 of the second group DRAM_G1.

That is to say, in each of the memory modules 220 and 230, a data busmay be coupled between the memory chip DRAM1 and the memory chip DRAM5,a data bus may be coupled between the memory chip DRAM2 and the memorychip DRAM6, a data bus may be coupled between the memory chip DRAM3 andthe memory chip DRAM7, a data bus may be coupled between the memory chipDRAM8 and the memory chip DRAM12, a data bus may be coupled between thememory chip DRAM9 and the memory chip DRAM13, a data bus may be coupledbetween the memory chip DRAM10 and the memory chip DRAM14, and a databus may be coupled between the memory chip DRAM11 and the memory chipDRAM15. The data buses coupled between these corresponding memory chipsmay be the same as the first and second data buses DATA_BUS1 andDATA_BUS2 which are illustrated in FIG. 2 for memory chips DRAM0 andDRAM 4. Illustration of all these data busses is omitted for the sake ofconvenience in illustration.

In the memory system of FIG. 2, the first memory module 220 maycommunicate with the memory controller 210 through the signal lines ofthe first group L_G0, and the second memory module 230 may communicatewith the memory controller 210 through the signal lines of the secondgroup L_G1.

In detail, the memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11 of thefirst group DRAM_G0 of the first memory module 220 may exchange datawith the signal lines of the first group L_G0 through the buffer chipsDB0 to DB3 of the first group DB_G0. The memory chips DRAM4 to DRAM7 andDRAM12 to DRAM15 of the second group DRAM_G1 of the first memory module220 may exchange data with the signal lines of the first group L_G0through the memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11 of the firstgroup DRAM_G0 and the buffer chips DB0 to DB3 of the first group DB_G0.

The memory chips DRAM4 to DRAM7 and DRAM12 to DRAM15 of the second groupDRAM_G1 of the second memory module 230 may exchange data with thesignal lines of the second group L_G1 through the buffer chips DB4 toDB7 of the second group DB_G1. The memory chips DRAM0 to DRAM3 and DRAM8to DRAM11 of the first group DRAM_G0 of the second memory module 230 mayexchange data with the signal lines of the second group L_G1 through thememory chips DRAM4 to DRAM7 and DRAM12 to DRAM15 of the second groupDRAM_G1 and the buffer chips DB4 to DB7 of the second group DB_G1.

In other words, in the memory system of FIG. 2, each of the memorymodules 220 and 230 uses for communication with the memory controller210 only one half of the signal lines (i.e., one of the first and secondgroups L_G0 and L_G1 of the signal lines) included in the channelCHANNEL.

To this end, in the case of the first memory module 220, the memorychips DRAM4 to DRAM7 and DRAM12 to DRAM15 of the second group DRAM_G1communicate with the memory controller 210 by using the buffer chips DB0to DB3 of the first group DB_G0, instead of the buffer chips DB4 to DB7of the second group DB_G1, through the memory chips DRAM0 to DRAM3 andDRAM8 to DRAM11 of the first group DRAM_G0.

Also, in the case of the second memory module 230, the memory chipsDRAM0 to DRAM3 and DRAM8 to DRAM11 of the first group DRAM_G0communicate with the memory controller 210 by using the buffer chips DB4to DB7 of the second group DB_G1, instead of the buffer chips DB0 to DB3of the first group DB_G0, through the memory chips DRAM4 to DRAM7 andDRAM12 to DRAM15 of the second group DRAM_G1.

For this operation, each of the plurality of memory chips DRAM0 toDRAM15 included in the first and second memory modules 220 and 230 mayinclude therein a path selection unit for selecting the path of data. Byusing such a path selection unit, the respective memory chips DRAM0 toDRAM15 of the respective first and second groups DRAM_G0 and DRAM_G1 mayoutput its data to a corresponding one of the buffer chips DB0 to DB7and may transfer the data of a corresponding memory chip of the otherone of the first and second groups DRAM_G0 and DRAM_G1 to thecorresponding one of the buffer chips DB0 to DB7. For example, each ofthe plurality of memory chips DRAM0 to DRAM15 may include a switchbetween its data path and the data path of the corresponding memorychip. Illustration of these switches is omitted for the sake ofconvenience in illustration.

In detail, in the first memory module 220, each of the memory chipsDRAM0 to DRAM3 and DRAM8 to DRAM11 of the first group DRAM_G0 mayexchange its data with a corresponding one of the buffer chips DB0 toDB3 of the first group DB_G0 in the case where a first path is selected.Further, in the first memory module 220, each of the memory chips DRAM0to DRAM3 and DRAM8 to DRAM11 of the first group DRAM_G0 may transferdata between a corresponding one of the memory chips DRAM4 to DRAM7 andDRAM12 to DRAM15 of the second group DRAM_G1 and the correspondingbuffer chip DB0 to DB3 of the first group DB_G0 through the data busDATA_BUS1 in the case where a second path is selected.

In the second memory module 230, each of the memory chips DRAM4 to DRAM7and DRAM12 to DRAM15 of the second group DRAM_G1 may exchange its datawith a corresponding one of the buffer chips DB4 to DB7 of the secondgroup DB_G1 in the case where a third path is selected. Further, in thesecond memory module 230, each of the memory chips DRAM4 to DRAM7 andDRAM12 to DRAM15 of the second group DRAM_G1 may transfer data between acorresponding one of the memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11of the first group DRAM_G0 and the corresponding buffer chip DB4 to DB7of the second group DB_G1 through the data bus DATA_BUS2 in the casewhere a fourth path is selected.

In the memory system of FIG. 2, the first memory module 220 may use thebuffer chips DB0 to DB3 of the first group DB_G0 and the signal lines ofthe first group L_G0 rather than the buffer chips DB4 to DB7 of thesecond group DB_G1 and the signal lines of the second group L_G1 whencommunicating with the memory controller 210, and the second memorymodule 230 may use the buffer chips DB4 to DB7 of the second group DB_G1and the signal lines of the second group L_G1 rather than the bufferchips DB0 to DB3 of the first group DB_G0 and the signal lines of thefirst group L_G0 when communicating with the memory controller 210.

FIG. 3 is a diagram illustrating path selection of one (e.g. DRAM0) ofthe memory chips DRAM0 to DRAM3 and DRAM8 to DRAM11 of the first groupDRAM_G0 in the first memory module 220. In FIG. 3, “CASE1” represents apath through which data is transferred in the case where the first pathis selected, and “CASE2” represents a path through which data istransferred in the case where the second path is selected.

Referring to “CASE1” when the first path is selected, the memory chipDRAM0 may transfer data between its internal circuit 301 and the bufferchip DB0 of the first group DB_G0. Referring to CASE2, in the case wherethe second path is selected, the memory chip DRAM0 may transfer datathrough the data bus DATA_BUS1 between the memory chip DRAM4 of thesecond group DRAM_G1 and the buffer chip DB0 of the first group DB_G0.

FIG. 4 is a configuration diagram illustrating a memory system accordingto another embodiment of the present invention.

Referring to FIG. 4, the memory system may include a memory controller410, a first memory module 420, and a second memory module 430.

The first and second memory modules 420 and 430 may include a pluralityof memory chips DRAM0 to DRAM15, respective registering clock drivers421 and 431, and a plurality of buffer chips DB0 to DB7.

In the memory system, one or more of the signal lines of a first groupL_G0 and one or more of the signal lines of a second group L_G1 may bedisposed alternately with each other. In the memory system of FIG. 4, itis exemplified that 4 signal lines of the first group L_G0 and 4 signallines of the second group L_G1 are disposed alternately with each other.

In the memory modules 420 and 430, the memory chips DRAM0 to DRAM15 maybe disposed in 2 rows and 8 columns. The memory chips DRAM0 to DRAM15included in each of the first and second memory modules 420 and 430 maybe divided into the memory chips DRAM0 to DRAM7 of a first group DRAM_G0disposed in a first row and the memory chips DRAM8 to DRAM15 of a secondgroup DRAM_G1 disposed in a second row.

Each of the buffer chips DB0 to DB7 may buffer the data transferredbetween the memory controller 410 and one or more corresponding memorychips among the plurality of memory chips DRAM0 to DRAM15.

Each of the buffer chips DB0 to DB7 of the first memory module 420 maybe coupled between two memory chips of the same column and one or more(e.g., four) signal lines of the first group L_G0. Each of the bufferchips DB0 to DB7 of the second memory module 430 may be coupled betweentwo memory chips of the same column and one or more (e.g., four) signallines of the second group L_G1.

The buffer chips DB0 to DB7 of the first memory module 420 may transferdata between the memory chips DRAM0 to DRAM15 of the first and secondgroups DRAM_G0 and DRAM_G1 of the first memory module 420 and the signallines of the first group L_G0, and the buffer chips DB0 to DB7 of thesecond memory module 430 may transfer data between the memory chipsDRAM0 to DRAM15 of the first and second groups DRAM_G0 and DRAM_G1 ofthe second memory module 430 and the signal lines of the second groupL_G1.

The memory chips DRAM0 to DRAM7 of the first group DRAM_G0 may exchangedata with the buffer chips DB0 to DB7 through lines A. Further, thememory chips DRAM8 to DRAM15 of the second group DRAM_G1 may exchangedata with the buffer chips DB0 to DB7 through lines B

FIG. 5 is a diagram illustrating a communication path between each oneof the memory chips DRAM0 to DRAM15 and the memory controller 410included in the memory system of FIG. 4.

Referring to FIG. 5, the memory chip DRAM0 of the first group DRAM_G0 ofthe first memory module 420 may communicate with the memory controller410 through the lines A connected to the buffer chip DB0 of the firstmemory module 420 and the signal lines of the first group L_G0 (“PATH1”in FIG. 5). The memory chip DRAM9 of the second group DRAM_G1 of thefirst memory module 420 may communicate with the memory controller 410through the lines B connected to the buffer chip DB1 of the first memorymodule 420 and the signal lines of the first group L_G0 (“PATH2” in FIG.5). The memory chip DRAM4 of the first group DRAM_G0 of the secondmemory module 430 may communicate with the memory controller 410 throughthe lines A connected to the buffer chip DB4 of the second memory module430 and the signal lines of the second group L_G1 (“PATH3” in FIG. 5).The memory chip DRAM13 of the second group DRAM_G1 of the second memorymodule 430 may communicate with the memory controller 410 through thelines B connected to the buffer chip DB5 of the second memory module 430and the signal lines of the second group L_G1 (“PATH4” in FIG. 5).

The path PATH2 may bypass the memory chip DRAM1 of the first memorymodule 420. The path PATH3 may bypass the memory chips DRAM4 and DRAM12of the first memory module 420 through the signal lines of the secondgroup L_G1. The path PATH4 may bypass the memory chip DRAM5 of thesecond memory module 430, and may bypass the memory chips DRAM5 andDRAM13 of the first memory module 420 through the signal lines of thesecond group L_G1.

Similarly to the memory system of FIG. 2, in the memory system of FIG.4, each of the memory modules 420 and 430 uses for communication withthe memory controller 410 only one half of the signal lines (i.e., oneof the first and second groups L_G0 and L_G1 of the signal lines)included in the channel CHANNEL. However, by changing connectionrelationship of the signal lines of the first and second groups L_G0 andL_G1, advantages are provided in that the data buses DATA_BUS1 andDATA_BUS2 of FIG. 2 are not needed.

FIG. 6 is a configuration diagram illustrating a memory system accordingto yet another embodiment of the present invention.

Referring to FIG. 6, the memory system may include a memory controller610, a first memory module 620, and a second memory module 630.

The first and second memory modules 620 and 630 may include a pluralityof memory chips DRAM0 to DRAM15, and registering clock drivers 621 and631, respectively. Unlike the memory chips of FIGS. 2 and 4, the memorychips of FIG. 6 may communicate with the memory controller 610 withoutusing buffer chips.

In the memory system, one or more of the signal lines of a first groupL_G0 and one or more of the signal lines of a second group L_G1 may bedisposed alternately with each other. In the memory system of FIG. 6, itis exemplified that 4 signal lines of the first group L_G0 and 4 signallines of the second group L_G1 are disposed alternately with each other.

In the memory modules 620 and 630, the memory chips DRAM0 to DRAM15 maybe disposed in 2 rows and 8 columns. The memory chips DRAM0 to DRAM15included in each of the first and second memory modules 620 and 630 maybe divided into the memory chips DRAM0 to DRAM7 of a first group DRAM_G0disposed in a first row and the memory chips DRAM8 to DRAM15 of a secondgroup DRAM_G1 disposed in a second row.

In FIG. 6, the memory chips DRAM0 to DRAM7 of the first group DRAM_G0 ofthe first memory module 620 may be coupled with one or more signal linesof the first group L_G0. In FIG. 6, the memory chips DRAM0 to DRAM7 ofthe first group DRAM_G0 of the second memory module 630 may be coupledto one or more signal lines of the second group L_G1.

The memory chips DRAM0 to DRAM7 of the first group DRAM_G0 and thememory chips DRAM8 to DRAM15 of the second group DRAM_G1 ofgeometrically corresponding disposition may respectively correspond toeach other. For example, referring to FIG. 6, the memory chip DRAM0 ofthe first group DRAM_G0 and the memory chip DRAM8 of the second groupDRAM_G1 have geometrically corresponding disposition (i.e., leftmostside of the first and second groups DRAM_G0 and DRAM_G1).

In the memory modules 620 and 630, data buses DATA_BUS1 and DATA_BUS2may be coupled between corresponding memory chips among the memory chipsDRAM0 to DRAM7 of the first group DRAM_G0 and the memory chips DRAM8 toDRAM15 of the second group DRAM_G1. For example, referring to FIG. 6,the memory chip DRAM0 of the first group DRAM_G0 and the memory chipDRAM8 of the second group DRAM_G1 are coupled to each other through thedata bus DATA_BUS1 in the first memory module 620. For example,referring to FIG. 6, the memory chip DRAM0 of the first group DRAM_G0and the memory chip DRAM8 of the second group DRAM_G1 are coupled toeach other through the data bus DATA_BUS2 in the second memory module630.

In the memory system of FIG. 6, the first memory module 620 maycommunicate with the memory controller 610 through the signal lines ofthe first group L_G0, and the second memory module 630 may communicatewith the memory controller 610 through the signal lines of the secondgroup L_G1.

In detail, the memory chips DRAM0 to DRAM7 of the first group DRAM_G0 ofthe first memory module 620 may directly exchange data with the signallines of the first group L_G0. The memory chips DRAM8 to DRAM15 of thesecond group DRAM_G1 of the first memory module 620 may exchange datawith the signal lines of the first group L_G0 through the memory chipsDRAM0 to DRAM7 of the first group DRAM_G0.

The memory chips DRAM0 to DRAM7 of the first group DRAM_G0 of the secondmemory module 630 may directly exchange data with the signal lines ofthe second group L_G1. The memory chips DRAM8 to DRAM15 of the secondgroup DRAM_G1 of the second memory module 630 may exchange data with thesignal lines of the second group L_G1 through the memory chips DRAM0 toDRAM7 of the first group DRAM_G0.

For this operation, each of the plurality of memory chips DRAM0 toDRAM15 included in the first and second memory modules 620 and 630 mayinclude therein a path selection unit for selecting the path of data. Byusing such a path selection unit, the respective memory chips DRAM0 toDRAM15 of the respective first and second groups DRAM_G0 and DRAM_G1 mayoutput its data to the signal lines coupled thereto and may transfer thedata of a corresponding memory chip of the other one of the first andsecond groups DRAM_G0 and DRAM_G1 to the signal lines coupled thereto.

In detail, in the first memory module 620, each of the memory chipsDRAM0 to DRAM7 of the first group DRAM_G0 may exchange its data with thesignal lines of the first group L_G0 in the case where a first path isselected. Further, in the first memory module 620, each of the memorychips DRAM0 to DRAM7 of the first group DRAM_G0 may transfer databetween a corresponding one of the memory chips DRAM8 to DRAM15 of thesecond group DRAM_G1 and the signal lines of the first group L_G0through the data bus DATA_BUS1 in the case where a second path isselected.

In the second memory module 620, each of the memory chips DRAM0 to DRAM7of the first group DRAM_G0 may exchange its data with the signal linesof the second group L_G1 in the case where a third path is selected.Further, in the second memory module 620, each of the memory chips DRAM0to DRAM7 of the first group DRAM_G0 may transfer data between acorresponding one of the memory chips DRAM8 to DRAM15 of the secondgroup DRAM_G1 and the signal lines of the second group L_G1 through thedata bus DATA_BUS2 in the case where a fourth path is selected.

FIG. 7 is a diagram illustrating a communication path between each oneof the memory chips DRAM0 to DRAM15 and the memory controller 610included in the memory system of FIG. 6.

Referring to FIG. 7, the memory chip DRAM0 of the first group DRAM_G0 ofthe first memory module 620 may communicate with the memory controller610 directly through the signal lines of the first group L_G0 (“PATH1”in FIG. 7). The memory chip DRAM9 of the second group DRAM_G1 of thefirst memory module 620 may communicate with the memory controller 610through the memory chip DRAM1 of the first group DRAM_G0 and the signallines of the first group L_G0 (“PATH2” in FIG. 7). The memory chip DRAM4of the first group DRAM_G0 of the second memory module 630 maycommunicate with the memory controller 610 directly through the signallines of the second group L_G1 (“PATH3” in FIG. 7). The memory chipDRAM13 of the second group DRAM_G1 of the second memory module 630 maycommunicate with the memory controller 610 through the memory chip DRAM5of the first group DRAM_G0 and the signal lines of the second group L_G1(“PATH4” in FIG. 7).

The path PATH2 passes through the memory chip DRAM1 of the first memorymodule 620 by the data bus DATA_BUS1. The path PATH3 may bypass thememory chips DRAM4 and DRAM12 of the first memory module 620 through thesignal lines of the second group L_G1. The path PATH4 passes through thememory chip DRAM5 of the second memory module 630 by the data busDATA_BUS2, and may bypass the memory chips DRAM5 and DRAM13 of the firstmemory module 620 through the signal lines of the second group L_G1.

FIG. 8 is a diagram illustrating path selection of one (e.g. DRAM0) ofthe memory chips DRAM0 to DRAM7 of the first group DRAM_G0 in the firstmemory module 620. In FIG. 8, “CASE1” represents a path through whichdata is transferred in the case where the first path is selected, and“CASE2” represents a path through which data is transferred in the casewhere the second path is selected.

Referring to “CASE1” when the first path is selected, the memory chipDRAM0 may transfer data between its internal circuit 801 and the signallines of the first group L_G0. Referring to “CASE2” when the second pathis selected, the memory chip DRAM0 may transfer data between an internalcircuit 802 of the memory chip DRAM8 of the second group DRAM_G1 thesignal lines of the first group L_G0 through the data bus DATA_BUS1

Excluding other signal lines, e.g., signal lines coupled to theregistering clock drivers 221, 231, 421, 431, 621 and 631, the signallines for the data communication of the memory controllers 210, 410 and610 and the memory modules 220, 230, 420, 430, 620 and 630 areillustrated.

In FIGS. 2, 4, 5, 6 and 7, a bundle of a plurality of lines isillustrated as one line. ‘Xk (k is a natural number)’ represents thatone line illustrated corresponds to k number of lines. For example, ‘X4’represents that one line illustrated corresponds to 4 lines. Forreference, the reference symbols ‘X4’ and ‘X8’ are given for theleftmost lies among the lines illustrated, for the sake of conveniencein illustration. However, it is to be understood that the remaininglines correspond to the same numbers of lines as the leftmost lines.

In the present technology, a channel for transferring signals between amemory module and a memory controller is configured in various methods,and through this, the loading of the channel may be reduced and thequality of signals may be improved.

Although various embodiments have been described for illustrativepurposes, it will be apparent to those skilled in the art that variouschanges and modifications may be made without departing from the spiritand scope of the invention as defined in the following claims.

What is claimed is:
 1. A memory module comprising: a first group ofmemory chips; a second group of memory chips coupled to the first groupof memory chips, respectively, through data buses; and a first group ofbuffer chips suitable for buffering data transferred between the firstgroup of memory chips and a first group of signal lines, the first groupof memory chips each include: a path selection unit suitable forselecting a first path between the first group of memory chips and thefirst group of buffer chips or a second path between the second group ofmemory chips and the first group of buffer chips.
 2. The memory moduleaccording to claim 1, wherein the first group of memory chips exchangedata stored therein with the first group of signal lines through thefirst group of buffer chips, when the first path is selected, whereinthe second group of memory chips exchange data stored therein with thefirst group of signal lines through the first group of memory chips andthe first group of buffer chips, when the second path is selected. 3.The memory module of claim 1, wherein the first group of memory chipsoutput data stored therein to the first group of buffer chips when thefirst path is selected, wherein the first group of memory chips transferdata between the data buses of the second group of memory chips and thefirst group of buffer chips when the second path is selected.
 4. Thememory module of claim 1, further includes a registering clock driver.5. The memory module according to claim 4, wherein the first group ofmemory chips are disposed on a first side of the registering clockdriver, and the second group of memory chips are disposed on a secondside of the registering clock driver.
 6. The memory module according toclaim 5, wherein the first group of buffer chips are disposed on thefirst side of the registering clock driver, and the first group ofsignal lines are coupled to the first group of buffer chips on the firstside of the first registering clock driver.
 7. A memory modulecomprising: a first group of memory chips coupled to a first group ofsignal lines, respectively; and a second group of memory chips coupledto the first group of memory chips, respectively, through data buses;the first group of memory chips each include: a path selection unitsuitable for selecting a first path between the first group of memorychips and the first group of signal lines or a second path between thesecond group of memory chips and the first group of signal lines.
 8. Thememory module according to claim 7, wherein the first group of memorychips exchange data stored therein directly with the first group ofsignal lines, when the first path is selected, wherein the second groupof memory chips exchange data stored therein with the first group ofsignal lines through the first group of memory chips, when the secondpath is selected.
 9. The memory module of claim 7, wherein the firstgroup of memory chips output data stored therein to the first group ofsignal lines when the first path is selected, wherein the first group ofmemory chips transfer data between the data buses of the second group ofmemory chips and the first group of signal lines when the second path isselected.
 10. The memory module according to claim 7, wherein the firstgroup of memory chips are disposed on a first row, and the second groupof memory chips are disposed on a second row.